1. Field of the Invention
The present invention relates to a circuit board formed by accommodating an electronic component such as a semiconductor element in an insulation layer, and to a method for manufacturing such a circuit board.
2. Discussion of the Background
Japanese Patent No. 4205749 describes an electronic module in which a semiconductor element is built into an insulation layer. The electronic module is manufactured by the following process: (1) On a copper foil with a carrier, a semiconductor element is mounted via an adhesive agent in such a way that a terminal faces downward; (2) An insulation layer is formed for encapsulating the semiconductor element; (3) The carrier is removed; (4) After the carrier is removed, an opening penetrating through the copper foil and the adhesive layer and reaching a pad of the semiconductor element is formed by a laser; and (5) A via is formed in the opening and a conductive pattern is also formed to be connected to the via. The contents of this publication are incorporated herein by reference in their entirety.